My U.S. Pat. No. 6,099,309, relates generally to a disposable prophy angle. Structure of this prophy angle is utilized to contain and support the present invention.
1. Field of the Invention
The present invention relates generally to an improved disposable contra-angle. More particularly, the present invention relates to disposable burs that can be placed into rotation for high speed drive.
2. Description of the Prior Art
Dental drill burs are well known in the art. At present, they are removably placed into the contra-angle by the dentist or the dental assistant. The standard procedure is for the dentist to place the bur into the contra-angle, and after the procedure it is removed manually to be brushed and sterilized. Often, it is discarded because of wear or inability to properly clean. Because the contra-angle is subject to contamination and infection from saliva and blood of the patient, it needs to be brushed; placed into ultrasonic; sterilized; and then lubricated before it can be used again. The lubrication is very critical due to the variable speeds generated by contra-angles. Extra care must be taken to prevent any oil from escaping into the patient's mouth or on the cavity itself. Occasionally the contra-angle must be taken apart because the gears have smudge accumulation and thereby have difficulty operating. This along with normal cleaning creates a substantial time loss leading to lower productivity of the entire dental office. All of this makes the use of reasonably priced contra-angles very practical. But beyond cost, the most important reason for using disposable contra-angles is to reduce the danger from incomplete sterilization, whereby the bacteria and infection are then transferred from one patient to another.
The main problems associated with the prior art is that the retained bur has a tendency to rattle and be generally noisy. This is primarily due to the fact that they are only connected at the superior end. There definitely is too much play between the cylinder of the bur and the core of the rotating mandrel. This results in energy loss, fatigue, loss of cutting efficiency. The patients feel all of this, and thus there can be an increase in anxiety in an already very stressful environment.
U.S. Pat. No. 5,766,008 issued to Hughes on Jun. 16, 1998, teaches what is the standard method of inserting a dental bit into the dental handpiece. One end of the shank's superior end being luted.
U.S. Pat. No. 5,749,728 issued to Bailey on May 12, 1998, teaches the use of a disposable dental angle. He uses a latch on the cap to lock the angle together. This latch is typical of the method employed in the prior art to contain the driving and driven gears and to retain a bur that is held therein.
U.S. Pat. No. 5,718,582 issued to Quinn et al. on Feb. 17, 1998, is illustrative of a patent that has a solution for the one of the most common problem encountered in dental handpieces, especially those that reach speeds of 400,000 rpm. This problem is rotation and axial slippage within the mandrel (chuck).
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.